Vitamin D Levels and Survival in Cancer Patients

Association of Pre-diagnostic Vitamin D Levels and Survival in Older Individuals With Cancer

Using the population-based data sources in Iceland and the well-characterized AGES-Reykjavik cohort, our overarching aims are on exploring whether pre-diagnostic serum levels of 25-hydroxyvitamin D (25(OH)D) among older individuals living in Iceland were associated with survival after cancer diagnosis. We also wanted to assess the risk of being diagnosed with cancer in association with 25(OH)D levels. In this population living just south of the arctic circle, vitamin D levels largely depend on dietary- and supplemental sources.

Study Overview

• Status: Completed
• Conditions: Neoplasms

• Study Type: Observational
• Enrollment (Actual): 5764

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 66 years to 98 years (Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Probability Sample

Study Population

In 1967, all 30,795 men and women living in the capital area of Iceland and born between 1907 and 1935 were invited by the Icelandic Heart Association to join a prospective cohort study. Approximately 19,000 attended the clinic at least once and became participants of the Reykjavik Study. Subsequently, in 2002, a random sample of the cohort comprising 5,764 men and women who were still alive in Iceland and aged 66 to 96 years entered the Ages Gene/Environment Susceptibility (AGES) - Reykjavik Study (20). Serum 25(OH)D was measured in 5,519 of all 5,764 (96%) participants at study entry in year 2002 through 2006.

Description

Inclusion Criteria:

To be part of the AGES-Reykjavik Study, initiated between 2002 and 2006.

Exclusion Criteria:

Diagnosed with cancer at study entry

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Overall mortality among cancer patients	We tested the association between pre-diagnostic 25(OH)D levels and total survival	Patients were followed from date of diagnosis since 2002 until death or censored at end of the follow-up (December 31, 2014)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Cancer-specific mortality among cancer patients	We tested the association between pre-diagnostic 25(OH)D levels and cancer survival	Patients were followed from date of diagnosis since 2002 until death or censored at end of the follow-up (December 31, 2014)

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Pre-diagnostic 25(OH)D levels and cancer risk	We tested the association between pre-diagnostic 25(OH)D levels and risk of being diagnosed with cancer	Participants without cancer were followed from the study entry since 2002 until cancer diagnosis, death or end of the observation period whichever occurred first (December 31, 2014)

Collaborators and Investigators

• Sponsor: Icelandic Heart Association
• Collaborators: University of Iceland

Publications and helpful links

Helpful Links

• Age, Gene/Environment Susceptibility-Reykjavik Study: Multidisciplinary Applied Phenomics

Study record dates

Study Major Dates

• Study Start (Actual): January 1, 2002
• Primary Completion (Actual): December 30, 2006
• Study Completion (Actual): December 30, 2006

Study Registration Dates

• First Submitted: August 28, 2017
• First Submitted That Met QC Criteria: August 28, 2017
• First Posted (Actual): August 30, 2017

Study Record Updates

• Last Update Posted (Actual): August 30, 2017
• Last Update Submitted That Met QC Criteria: August 28, 2017
• Last Verified: August 1, 2017

More Information

Terms related to this study

• Other Study ID Numbers: HI14010102